Nebulizers may be employed to deliver a fluid as a mist. For example, in medical applications, nebulizers may be used as drug delivery devices for delivering medication to a patient in the form of a mist that may be inhaled by the patient. As another example, water (e.g., heated water) may be delivered from a nebulizer to a patient to be inhaled for humidification. Various nebulizers may utilize oxygen, ultrasonic power (e.g., vibrations), and/or compressed air to provide droplets (e.g., aerosol droplets or mist) from solutions or suspensions. The droplets may then be inhaled, for example using a facemask operably connected to the nebulizer.
For example, certain nebulizers may employ ultrasonic vibrations to provide a mist. In some nebulizers, an electronic oscillator is used to generate a high frequency ultrasonic wave, which in turn causes a mechanical vibration of a piezoelectric element. The vibrating piezoelectric element, if in contact with a liquid (e.g., a liquid in a reservoir), may then cause a mist to be provided from the liquid. As another example, in some known nebulizers, a piezoelectric element is affixed to a mesh or membrane at an end of a liquid reservoir. Vibration of the piezoelectric element causes a vibration of the mesh or membrane and results in the passage of droplets through the mesh or membrane. Such nebulizers, however, suffer from a variety of drawbacks. For example, such nebulizers typically utilize a generally large reservoir, resulting in excessive dead volume and waste. Further, as the volume in the reservoir changes, the rate of mist production may become difficult to measure and/or control. Further still, the piezoelectric element may be affixed to the mesh or membrane, resulting in high costs of replacement (as the piezoelectric element and mesh are disposed together) and/or contamination of the piezoelectric element. Further still, such nebulizers may typically operate in only one given orientation, limiting the versatility or flexibility of use of the device.